The present invention relates to a slide ring seal for sealing rotating machine components, in particular shafts; the seal comprises a housing in which are disposed/primary seal constructed as slide ring, and a bellows-like secondary seal, the latter being axially fixed with at least one spring with respect to the slide ring, which bears on a slide face of a counter ring which is adapted to be secured on the shaft with force fit and with which an axial stop limitation is associated.
According to one known slide ring seal of this type (German Offenlegungsschrift No. 25 31 749) the counter ring is pressed in a rigid and medium-sealing manner into a sleeve end which is bent outwardly in cross-section in an L-shape, accompanied by the interposition of a rubber packing. The sleeve is mounted over its entire length with force fit on the rotating machine component. The stop limitation is formed by the other end of the sleeve, which widens outwardly in a funnel-like manner.
Because of its end which receives the counter ring, the relatively long sleeve portion, and the widened end, the sleeve is of complicated construction and therefore expensive to make. The assembly of the complete counter ring is also complicated because three parts, i.e. counter ring, rubber packing, and holding means, must be assembled together. In addition, the rubber ring and the counter ring must be exactly aligned with respect to the sleeve part and also with respect to each other to ensure that the slide face of the counter ring lies as perpendicular as possible to the axis of the rotating machine component to minimize the plane running deviation of the counter ring slide face. Due to inevitable form deviations of these individual parts, and the additional position deviations which occur during assembly, it is hardly possible to align the slide face of the counter ring exactly with respect to the rotating machine component, so that when the machine component rotates, the counter ring exhibits a wobble movement which subjects the slide ring seal to premature wear. In addition, the slide face of the counter ring cannot be refinished by machine lapping because the sleeve of the holding means projects beyond the slide face. If the complete seal unit is opened for inspection purposes or for refinishing, i.e. the counter ring must be removed from the slide ring seal, the sleeve must be destroyed, so that it cannot be used again.
It is an object of the present invention to construct a seal of the aforementioned general type in such a manner that with low production costs and only a small number of components, the counter ring can be assembled in a simple technical manner to give an extremely accurate alignment with respect to the rotating machine component, so that a wobble movement when the latter rotates is avoided.